proff of concept test and consumer level service suggestion

I am looking for someone with access to plasma or flame spray to test a concept. I recently bought a magnetic induction hot plate [not NuWave - FWIW s/h costs for the
second "free" NuWave unit and "free" pots/pans is more than the unit.] and while I have several induction ready pieces of cook ware, I got to wondering why the other items I had could not be adapted.
Some web research indicates the heating mechanism is ohmic heating from eddy currents in the pan rather than hysteresis loss as I had assumed. The reason aluminum and copper pans won't work with normal induction cook tops is that the magnetic field penetrates the material too deeply and the induced current is flowing across too big a conductor cross section with not enough resistance. Some very expensive units use a much higher frequency induction circuit and these will work with aluminum and copper because of the reduced skin depth, but are expensive and in limited distribution. Additionally, pyroceramics/glass-ceramics won't work because eddy currents can't be induced in a non conductor.
Also came across a "stunt" on You Tube where aluminum foil is ignited with a induction cook top. The foil is so thin [1/2 mill] the cross section the induced current flows through is small enough to generate enough heat to melt/ignite it.
My thought is to plasma or flame spray an insulating layer on the bottom of the alumium/copper cook ware, then a thin layer of a conductive material, c. 0.5 mil or possibly thinner, then one or more thicker coats of a protective ceramic over the conductive film. Of course for the glass-ceramics there would be no need for the first insulating layer, just a thin metallic film, and one or more protective layers.
It does not appear that the metallic layer need be magnetic if it is thinner than the skin effect depth so nichrome, molybdenum, etc. may be better than iron, and it may be helpful to provide multiple metallic layers separated by insulating layers on the aluminum/copper cook ware.
The optimum "pattern" for the eddy current layer is unknown, and while a simple uniform surface works well, it may be that the efficiency could be improved by some sort of greek key pattern, radial spokes, closed loops, etc., which should be possible to produce with a stencil or mat, possibly computer cut, when the eddy current layer is applied.
A thin metallic layer on the bottom of the glass-ceramics would prevent their use in microwave ovens, much as you can't use aluminum foil or aluminized packaging, but there may be some configuration that will allow adequate eddy current induction/heating at 20-30 kHz, but will be "invisible" at microwave oven frequencies [c 4.5 gHz]
Any thoughts? This could be a good profit opportunity for someone with flame/plasma spray capability. Feel free to run with the ball. Tons of Corningware / Visions out there. It would be good to see some high tech processes at the cottage industry level
Below are some of the more interesting sites I came across. The enameled cast iron ware prices will make your socks roll up and down several times (and can't be used in a microwave)
http://en.wikipedia.org/wiki/Glass-ceramic
http://en.wikipedia.org/wiki/Pyroceram
http://en.wikipedia.org/wiki/Induction_cooking
http://commons.wikimedia.org/wiki/File:Foil_on_induction_cooktop.jpg
http://en.wikipedia.org/wiki/Aluminium_foil "Standard household foil is typically 0.016 millimetres (0.6 mils) thick and heavy duty household foil is typically 0.024 millimetres (0.9 mils)."
http://en.wikipedia.org/wiki/Skin_effect
http://commons.wikimedia.org/wiki/File:Skin_depth_by_Zureks.png
http://www.ceramcor.com/ceramic-skillet-fridgex-special http://www.ceramcor.com/aboutxtrema/
http://hypertextbook.com/facts/1998/HowardCheung.shtml
http://www.replacements.com/webquote/CORVISA.htm?s1=KX&2334288&gclid=CMijprWt3bYCFUyY4Aod1zwAIw
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Unka' George

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F. George McDuffee wrote:

You IDIOT! You have just completely BLOWN your chance to get a patent on this by this disclosure!
Jon
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On Mon, 22 Apr 2013 13:46:48 -0500, Jon Elson

============I got more suggestions and good ideas than I can ever use. A patent is a license to sue. I am 74 and no longer give a shit.
I just hope there is someone out there than can make use of this, if it indeed works. I have no idea how critical the spray process will be, but hopefully it is simple enough that shops with a low line manual flame or arc spray gun can do this for local walk ins.
2nd idea is to flame/plasma spray food grade nickel/stainless on the interior of cast iron cook ware for corrosion protection and nickle on the bottoms to avoid scratching the ceramic cook tops.
Alternative if you have nickel rack plate capability is to plate the entire pot/pan, possibly after grinding/sanding the as cast interior finish smooth and polishing or as an alternative to fired enamel, plasma spray ceramic or even TiN/PVD. For enameled CI see [be setting down] (Amazon.com product link shortened) (remember these are the *DISCOUNT* prices)
For a commercial attempt to do this using Chinese castings see: (Amazon.com product link shortened) Their QC seems to need attention...
"The skillet arrived with a "hole" in the cooking surface about the size of a pinhead. I was very concerned about this and tried to contact Olvida directly about it. Turns out Olvida is just a marketing label and this product is turned out by a small plating foundry in the Eastern United States. After expressing my concern about the hole, I was told not to worry about it as the nickel plating was 100% covered and was safe to use.
Still not convinced, I cooked up a pair of cheap pieces of meat just to put it through a single use cycle. Olive oil, pork, spices - it cooked evently but was an absolute pain to clean. The finish was marred, discolored and showed very uneven heating discoloration. I followed the directions for cleaning and then put it in the dishwasher once it cooled.
When I pulled it out, that single pin hole I was concerned about showed it's true colors. Rust. The assurances that I was given that the product was safe and as described were false."
and
"Unfortunately, my pan arrived with many tiny holes. I didn't think they'd be a problem until I put it in the dishwasher. That's when the first rust spot appeared. I called the company and they were very nice, fairly quickly sending me a replacement.
As I said, I really wanted to like this pan. Sadly, the same thing happened again. It came out of the dishwasher and had another rust spot. Not only that, but the pan became discolored (which probably wasn't a problem), and a large crack appeared by the handle." ---------------
I think nickel plating high quality American made CI cook ware with tight control of the plating would be much better. You can buy Lodge through Amazon or Walmart, but to see what is available http://www.lodgemfg.com/
several good foundry videos at http://www.lodgemfg.com/videos
Anyone with flame spray or rack nickel capability want to take a flyer? I will provide 10 "Double Dutch Ovens" from Lodge pre paid to your location, you apply the nickel and/or plasma ceramic and we can see how well they sell on ebay (and split the profits if any). http://www.lodgemfg.com/CatalogueRetrieve.aspx?ProductID &27389&A=SearchResult&SearchIDA06330&ObjectID&27389&ObjectType'
--
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F. George McDuffee wrote:

I was mostly kidding when I wrote that! I think that I have heard of such cookware, but I don't remember what it was called. I just designed a PC board for a lady that has applied for a patent for a drug store cosmetic-like item, I think she has wasted her money. Patents may be important to Apple, Samsung, IBM, etc. but they are not worth much to us little guys.
Jon
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On Mon, 22 Apr 2013 13:46:48 -0500, Jon Elson

============I got more suggestions and good ideas than I can ever use. A patent is a license to sue. I am 74 and no longer give a shit.
I just hope there is someone out there than can make use of this, if it indeed works. I have no idea how critical the spray process will be, but hopefully it is simple enough that shops with a low line manual flame or arc spray gun can do this for local walk ins.
2nd idea is to flame/plasma spray food grade nickel/stainless on the interior of cast iron cook ware for corrosion protection and nickle on the bottoms to avoid scratching the ceramic cook tops.
Alternative if you have nickel rack plate capability is to plate the entire pot/pan, possibly after grinding/sanding the as cast interior finish smooth and polishing or as an alternative to fired enamel, plasma spray ceramic or even TiN/PVD. For enameled CI see [be setting down] (Amazon.com product link shortened) (remember these are the *DISCOUNT* prices)
For a commercial attempt to do this using Chinese castings see: (Amazon.com product link shortened) Their QC seems to need attention...
"The skillet arrived with a "hole" in the cooking surface about the size of a pinhead. I was very concerned about this and tried to contact Olvida directly about it. Turns out Olvida is just a marketing label and this product is turned out by a small plating foundry in the Eastern United States. After expressing my concern about the hole, I was told not to worry about it as the nickel plating was 100% covered and was safe to use.
Still not convinced, I cooked up a pair of cheap pieces of meat just to put it through a single use cycle. Olive oil, pork, spices - it cooked evently but was an absolute pain to clean. The finish was marred, discolored and showed very uneven heating discoloration. I followed the directions for cleaning and then put it in the dishwasher once it cooled.
When I pulled it out, that single pin hole I was concerned about showed it's true colors. Rust. The assurances that I was given that the product was safe and as described were false."
and
"Unfortunately, my pan arrived with many tiny holes. I didn't think they'd be a problem until I put it in the dishwasher. That's when the first rust spot appeared. I called the company and they were very nice, fairly quickly sending me a replacement.
As I said, I really wanted to like this pan. Sadly, the same thing happened again. It came out of the dishwasher and had another rust spot. Not only that, but the pan became discolored (which probably wasn't a problem), and a large crack appeared by the handle." ---------------
I think nickel plating high quality American made CI cook ware with tight control of the plating would be much better. You can buy Lodge through Amazon or Walmart, but to see what is available http://www.lodgemfg.com/
several good foundry videos at http://www.lodgemfg.com/videos
Anyone with flame spray or rack nickel capability want to take a flyer? I will provide 10 "Double Dutch Ovens" from Lodge pre paid to your location, you apply the nickel and/or plasma ceramic and we can see how well they sell on ebay (and split the profits if any). http://www.lodgemfg.com/CatalogueRetrieve.aspx?ProductID &27389&A=SearchResult&SearchIDA06330&ObjectID&27389&ObjectType'
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Unka' George

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message

http://www.medscape.com/viewarticle/753985 "...that manifests itself after recurrent contact with the metal."
jsw
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